Short protection device for alternator
AssigneeMobiletron Electronics Co., Ltd.
InventorChien-Wen Chen
Life of this patent
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Abstract
A short circuit protection device for the protection of an alternator in which turning on/off a trigger switch causes conduction/cutoff of the field current of the field coil of the alternator is disclosed. The protection device enables the field current to pass through a sensor so that when the field current is abnormally high and the voltage drop across the sensor rises, the potential of an input end of a boost circuit electrically connected to the sensor correspondingly arises and an output end of the boost circuit electrically connected to a shutoff device drives the shutoff device to turn off the trigger switch, and the boost circuit further keeps the shutoff device in on-state to hold the trigger switch off till the short circuit condition is eliminated and the protection circuit system is reset.
Claims10
A short circuit protection device installed in an alternator to control the field current produced by a field coil of said alternator, the short circuit protection device comprising:
- a trigger switch electrically connected to said field coil and operated in such a manner that turning on/off said trigger switch corresponds to pass/cut-off said field current;
- a sensor having a current input node and a current output node respectively and electrically connected to said trigger switch and grounding potential, said sensor passing said field current when said trigger switch is turned on;
- a boost circuit comprising an input end and an output end, said input end being electrically connected to the current input node of said sensor;
- when the potential at said input end rises, the potential at said output end rises;
- when the potential at said input end drops, the potential at said output end remains unchanged;
- and
- a shutoff device comprising an upper conduction end, a lower conduction end, and a control end, which are respectively and electrically connected to said trigger switch, grounding potential, and the output end of said boost circuit, when the potential at said control end reaches a predetermined critical potential, said upper conduction end is conducted with said lower conduction end so as to turn off said trigger switch.
Dependencies are inferred from the claim text.